Sound deadening panel



July 1, 1947. 1.. r. MILNOR scum) DEADENING PANEL Filed June 13, 1944 INVENTOR. /d4zL 2% M Patented July 1, 1947 SOUND DEADENING PANEL Leland T. Milnor, Cincinnati, Ohio, assignor to The Cincinnati Manufacturing Company, Cincinnati, Ohio, a corporation of Ohio Application June 13, 1944, Serial No. 540,125

1 Claim. (Cl. 189-34) This invention relates to improvements in panels for the construction oi wall, ceilings and partitions of buildings or compartments and for coverings therefor, particularly for acoustical treatment and primarily for sound insulating, absorbing and deadening purposes.

In accordance with the present prevailing practice for acoustical insulation and from which highly efficient sound absorbing and sound deadening results are obtained and for structural stability and durability particularly for walls and partitions for aircraft engine testing rooms, it is customary to have the construction composed of suitably spaced metal facing sheets, the facing sheets for either one or both sides of the wall perforated or foraminous. The size of perforation, distance between perforations, or the ratio of perforated and non-perforated areas are governed to produce certain results without undue weakening of the sheets. The spacing between the sheets, as a backing for the sheets, is packed with a fibrous sound absorbing material, as for example,

glass wool. Y

The perforations in the facing sheet reduces its degree as a deflector of sound, provide passages for the transmission of sound to the sound absorbing material confined by the'sheets and exposes an apparently continuous surface to the stun-id waves. The perforations in order to prop- ,erly confine the sound absorbing backing material. must therefore, necessarily be of reduced or particularly limited diameter to prevent the fibers of the sound absorbing material from projecting or protruding therethrough, as well as the spacing between the perforations to obtain the desired efficiency.

To facilitate in erection, change in room size, or relocation. the wall is preferably of panel arrangement, providing for prefabrication and the panels in their individual form, before assembly into a wall structure can, in a horizontal plane, he more expeditiously packed with the fibrous material. than when disposed vertically in the process of wall erection.

It is desirable to have the fibrous sound-absorbing material compressively packed within the pacing filled thereby, so that its compactness, in a wall. will offer suflicient stability to avoid any appreciable settling, or downward movement due to any vibration to which the wall may be subiected, which would reduce its efficiency for certain portions, and particularly when the wall is utilized and subjected to severe vibration, as a muffler of sound, for testing rooms for aircraft motors with propeller attached.

It is common practice to construct the panels of a length to room size heighth to be erected vertically. usually consisting of a channel bar frame with the channel exposed outwardly and the perforated facing sheets marginally overlapping the outer side of the flanges of the bars for each side of the frame and welded thereto. Due to the length of the panel considerable cross strutting or bracing is required to obtain the necessary stability, adding to the cost of construction and weight. As the welding is usually at determinately spaced spots about the frame, it has been experienced that there is a large percentage of loosening due to imperfect fusion of the metal, as the perforated sheets do not lend themselves adequate for a good welding job without extreme care'to obtain a satisfactory bond and to avoid preceptible marring of the exposed side of the facing sheets. The use of mechanical fasteners, is tedious in its application, expensive and requires the heads to be countersunk, or results in objection in making a satisfactory connection with the vertical studding with which the panel is marginally interfitted or engaged for wall erection.

With the methods heretofore employed it was necessary in securing the facing sheets to the frame to have the channel exposed outwardly, effecting a spacing which is required to be packed during the process of wall erection, which is laborious andcostly.

Therefore an object of the invention is to provide a sound-absorbing or sound-deadening wall or ceiling structure composed of prefabricated panels or units ready for assembly in the erection of a wall or application over an erected wall, the panels each consisting ofQa channel bar frame as a support for facing sheets marginally bound and confined within the frame by a slip joint connection, with the web of the channel bar frame providinga flush edge for the panel, and the panel interiorly packed xvii-i a fibrous sound-1 absorbing material.

Another object is to provide a prefabricated panel of increased stability, simple in construction, in which the metal parts are interflttingly joined for quick and easy assembly and at a reduction in the production cost of the panel.

Various other features and advantages of the invention are more fully set forth in the following description of the accompanying drawings forming a part hereof and exemplifying a preferred embodiment, in which:

Figure 1 is a plan view of several prefabricated 1 sound-absorbing panels in a wall assembly with the face of the panels broken to illustrate the interior insulating packing.

Figure 2 is a section on line 2, 2, Figure 1, with the facing sheet for one side shown solid.

Figure 3 is an enlarged horizontal section through a panel having its opposite ends each respectively engaged within a support or studding.

Figure 4 is a plan view of a panel in the process of fabrication having one of its face sides open for packing in the sound-absorbing material or insulation.

Figure 5 is a cross-section of the channel bar forming the frame of the panel.

Referring to the drawings and in particular Figures 3 to 5 inclusive, l indicates the frame of the panel composed of a channel bar preferably of a single length, to accommodate for the full outline dimension of the panel, to avoid an undue number of joints. The frame therefore is constructed of a continuous bar length, longitudinally of uniform cross-sectional formation, facilitating its manufacture. The bar in its channel form in cross-section has each of its opposite flanges 2, 2, of inward double lap fold, longitudinally, provided an inner U-bend 3, with the groove formed thereby, open to the edge of the flange and forming a seam for the reception or socketing of a margin of a facing plate or sheet 4, perforated or otherwise. The double reverse fold longitudinally of each of the flanges of the bar serves as a reinforcement therefor giving added stability and strength to the bar, as well as providing sockets for the facing sheets of the panels.

The double fold is preferably inward, to conceal the raw edges of the metal and more favorable mechanically, as the margins of the facing sheet bear against a double thickness of metal, leaving no opportunity of a single metal thickness edge exposure liable to become bent in transportation handling of the panels.

To shape the bar into a rectangular frame, its flanges have V or miter cuts 5, therein located at definite points, proportionate for a given frame or panel dimension, with a mitering inward from each of the longitudinal ends of the bar, to permit the end portions to be bent to a lateral-position and into alignment to form one side of the frame so that the joint is intermediate of its length, and preferably for a side of the frame to be engaged within a channel of a studding or support. This however, is optional of advantage for the type of wall installation illustrated in Figure 1, particularly if the joint is welded, for any blemish resulting from the welding or other mode of making a joint connection would be concealed or hidden by the studding or support, which is a factor when wall finish is required.

After mitering the bar, it is bent into semiframe form, leaving the opposite end portions outstanding, to be closed in after the application of the facing sheets and sound-absorbing insulation, Initially after the bar has been bent into its semi-frame form, one of the facing sheets is inserted in place in the seam grooves of a relative flange of a pair of opposite side bars and an end bar of the frame and into full engagement therewith. This, with the frame sustained in a horizontal plane, leaves the upper side open for conveniently and compactl filling in the fibrous sound-absorbing material or other insulating packing, whereupon the second facing sheet can be easily slipped into place, and the opposite free ends of the bar, forming a side of the frame, can readily be bent laterally inward into alignment and seaming connection with the relative and margins to the two spaced facing sheets and the joint ends of the bars secured together as by welding or otherwise.

The slip joint or seam connection of the panel frame and facing sheets provides an efficient assembly of the parts without the use of any auxiliary fastening means, or Welding, materially facilitating and reducing the cost of fabrication. Th facing sheets are free to flex without resistance when the wall is subjected to heavy vibration, dampening the sound waves, and do not possess drum-like characteristics as when rigidly marginally affixed to the framing.

In a wall assembly, shown in Figure l as an example, a plurality of panels are disposed one upon another for the heighth of the wall, each having its opposite ends respectively engaged in a channel of a relative studding 8, preferably of I-form in cross-section, with the flush edge of the panel in abutting contact with the web of the studding, This eliminates any vacant spacing which would require filling with insulation during the process of wall erection as necessary with the heretofore prevailing forms of construc tion.

The panels having their greater lengthwise dimension disposed horizontally, increases the paneling area between studding, over the commonly employed single sheet facings for the full wall or partition heighth, limited in width to the standard available of metal sheet material, and which require considerable bracing, longitudinally and crosswise to give the necessary stability,

and which is also necessary for tying and sustaining the sound-absorbing material against settling, particularly when the wall is subjected to heavy vibrations. The single wall heighth units add difficulty in erection and are bulky for handling in transportation.

The double lapping of the flanges of the channel bar framing increases the stability of the panel to a degree that a lighter gauge of sheet metal can be employed, reducing its load weight for the square foot area of a wall or ceiling and should it equal that of a single facing sheet wall paneling, between studding, this is offset by an increase in wall paneling area between studding, to a reduction in the number of studding.

The panels can be uniformly sized proportion ately to a given wall area for a symmetrical arrangement and thereby avoid odd or fractional sizes. The flush edging of the panels also permits assembl in connection with a wall or independent thereof for the forming of compartments, as a telephone booth or stall.

It is recognized that the size of panels is optional and that the forming of channel framing and method of application of the facing sheets for a panel assembly and packing in of the insulation, is applicable for single wall heighth of panels, and could. be equally manually performed at the place of installation and erection, as well as avoiding any necessity of bracing within the frame.

Having described my invention, I claim:

A prefabricated sound-absorbing panel for ready assembly in the erection of a wall or other structure, the panel comprising: a rectangular frame with the side rails thereof formed of a channel bar, the outer side of the web of the channel bar being plane surfaced and each flange thereof having a portion bent inwardly thereupon for the length of the flange and of U-shape in cross-section, laminating the flange and providing a groove iongitudinaily o! and open to the edge of the flange, a foraminous metal sheet respectively for each face side of the panel, each having its margin; engaged and socketed respectively into the groove of a relative flange of the side rails of the frame to confine and bind the sheet within the frame, and an insulating and sound-absorbing material compactly filling the hollow interior formed by said channel bar frame and said sheets.

LELAND T. MIL-NOR.

REFERENCES CITED The following references are of record in the tile 01 this patent:

Number Pinney Jan. 14, 1941 

